/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.planner.plan.nodes.exec.stream;

import org.apache.flink.api.dag.Transformation;
import org.apache.flink.streaming.api.transformations.OneInputTransformation;
import org.apache.flink.table.api.TableConfig;
import org.apache.flink.table.api.config.ExecutionConfigOptions;
import org.apache.flink.table.data.RowData;
import org.apache.flink.table.planner.codegen.WatermarkGeneratorCodeGenerator;
import org.apache.flink.table.planner.delegation.PlannerBase;
import org.apache.flink.table.planner.plan.nodes.exec.ExecEdge;
import org.apache.flink.table.planner.plan.nodes.exec.ExecNode;
import org.apache.flink.table.planner.plan.nodes.exec.ExecNodeBase;
import org.apache.flink.table.planner.plan.nodes.exec.InputProperty;
import org.apache.flink.table.planner.utils.JavaScalaConversionUtil;
import org.apache.flink.table.runtime.generated.GeneratedWatermarkGenerator;
import org.apache.flink.table.runtime.operators.wmassigners.WatermarkAssignerOperatorFactory;
import org.apache.flink.table.runtime.typeutils.InternalTypeInfo;
import org.apache.flink.table.types.logical.RowType;

import org.apache.calcite.rex.RexNode;

import java.util.Collections;
import java.util.Optional;

/** Stream {@link ExecNode} which generates watermark based on the input elements. */
public class StreamExecWatermarkAssigner extends ExecNodeBase<RowData>
        implements StreamExecNode<RowData> {
    private final RexNode watermarkExpr;
    private final int rowtimeFieldIndex;

    public StreamExecWatermarkAssigner(
            RexNode watermarkExpr,
            int rowtimeFieldIndex,
            InputProperty inputProperty,
            RowType outputType,
            String description) {
        super(Collections.singletonList(inputProperty), outputType, description);
        this.watermarkExpr = watermarkExpr;
        this.rowtimeFieldIndex = rowtimeFieldIndex;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected Transformation<RowData> translateToPlanInternal(PlannerBase planner) {
        final ExecEdge inputEdge = getInputEdges().get(0);
        final Transformation<RowData> inputTransform =
                (Transformation<RowData>) inputEdge.translateToPlan(planner);

        final TableConfig tableConfig = planner.getTableConfig();
        final GeneratedWatermarkGenerator watermarkGenerator =
                WatermarkGeneratorCodeGenerator.generateWatermarkGenerator(
                        tableConfig,
                        (RowType) inputEdge.getOutputType(),
                        watermarkExpr,
                        JavaScalaConversionUtil.toScala(Optional.empty()));

        final long idleTimeout =
                tableConfig
                        .getConfiguration()
                        .get(ExecutionConfigOptions.TABLE_EXEC_SOURCE_IDLE_TIMEOUT)
                        .toMillis();

        final WatermarkAssignerOperatorFactory operatorFactory =
                new WatermarkAssignerOperatorFactory(
                        rowtimeFieldIndex, idleTimeout, watermarkGenerator);

        return new OneInputTransformation<>(
                inputTransform,
                getDescription(),
                operatorFactory,
                InternalTypeInfo.of(getOutputType()),
                inputTransform.getParallelism());
    }
}
